const CODE: [usize; 8] = [100, 50, 30, 20, 10, 5, 2, 1];
pub fn dp_rec_mc(amount: u32) -> u32 {
    let mut amount = amount as usize;
    let mut ret = 0;
    for i in CODE {
        ret += amount / i;
        amount -= i * (amount / i);
    }
    ret as u32
}
